Medical Retrieval Device

ABSTRACT

A medical retrieval tool including a sheath; and a basket device connected to the sheath. The basket device includes a shaft and a basket located at a distal end of the shaft. The shaft is movably located in the sheath. The basket includes a first basket cage section and a second basket cage section. The first basket cage section is located in front of the second basket cage section. The basket is configured to be extended from a distal end of the sheath in a plurality of deployment modes including a first deployment mode where the first basket cage section is deployed in a first fully expanded shape and the second basket cage section is located in the sheath; and a second deployment mode where both the first basket cage section and the second basket cage section are deployed out of the distal end of the sheath.

BACKGROUND Technical Field

The exemplary and non-limiting embodiments relate generally to anendoscope and, more particularly, to an apparatus used with anendoscope.

Brief Description of Prior Developments

U.S. Pat. No. 6,764,499 discloses a medical device with a basket. U.S.Pat. No. 8,211,115 discloses a variable size retrieval basket.

SUMMARY

The following summary is merely intended to be exemplary. The summary isnot intended to limit the scope of the claims.

In accordance with one aspect, an example embodiment is provided in amedical retrieval tool comprising a sheath; and a basket deviceconnected to the sheath, where the basket device comprises a shaft and abasket located at a distal end of the shaft, where the shaft is movablylocated in the sheath. The basket comprises a first basket cage sectionand a second basket cage section and the first basket cage section islocated in front of the second basket cage section. The basket isconfigured to be extended from a distal end of the sheath in a pluralityof deployment modes comprising: a first deployment mode where the firstbasket cage section is deployed in a first fully expanded shape and thesecond basket cage section is located in the sheath; and a seconddeployment mode where both the first basket cage section and the secondbasket cage section are deployed out of the distal end of the sheath.

In accordance with another aspect, an example method comprises providinga basket device, where the basket device comprises a basket formed by aplurality of legs comprising superelastic material, where the legs areconnected at distal ends of the legs; shape setting, by a first heatsetting, at least a first portion of the legs to have a first shape; andshape setting, by a second heat setting, at least a second portion ofthe legs to have a second different shape.

In accordance with another aspect, an example method comprises forming abasket device, where the basket device comprises a basket at a distalend of a shaft, where the basket comprises a plurality of legs forming afirst shape with a first basket cage section and a second basket cagesection, where the first basket cage section is located in front of thesecond basket cage section, and where the first basket cage section issmaller than the second basket cage section; and shape setting at leasta portion of the basket to have a different second shape when the basketis subjected to a shape-memory transition stress and/or temperature,where the different second shape comprises a basket cage which is largerthan the second basket cage section.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features are explained in the followingdescription, taken in connection with the accompanying drawings,wherein:

FIG. 1 is a side view of an endoscope;

FIG. 2 is a side view of a distal end of an endoscopic tool;

FIG. 3 is a side view illustrating extension of the tool shown in FIG. 2from the distal end of the endoscope shown in FIG. 1;

FIG. 4 is a side view of the tool showing the basket device at aretracted position in the sheath of the tool;

FIG. 5 is a side view of the tool showing the basket device at a firstdeployed configuration;

FIG. 6 is a side view of the tool showing the basket device at a seconddeployed configuration; and

FIG. 7 is a side view of the tool showing the basket device at a thirddeployed configuration.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIG. 1, there is shown a side elevation view of anapparatus 10 incorporating features in an example embodiment. Althoughthe present invention will be described with reference to theembodiments shown in the drawings, it should be understood that thepresent invention can be embodied in many alternate forms ofembodiments. In addition, any suitable size, shape or type of elementsor materials could be used.

The apparatus 10 in this example is an endoscope medical deviceconfigured to be partially inserted into a patient's body, such as inthrough the patient's urethra for example. The endoscope 10 generallycomprises a control section 12 and a flexible or semi-flexible shaftconnected to the control section 12. The control section 12 forms ahandle for the apparatus. The shaft 14 includes a passive deflectionsection 16 and an active deflection section (bending section) 18 at thedistal end of the shaft 14. A control system 22 to control the activedeflection section 18 extends from the control section 12 to the activedeflection section 18. The control system 22 generally comprises bendingcontrol wires, wire sheaths, and an actuator 28. The wires are connectedto the actuator 28 at one end and are connected to the active deflectionsection 18 at a second end.

In the example embodiment shown, the control Section 12 has a useroperated slide or lever (control lever) 30. The lever 30 is connected tothe actuator 28. The actuator 28 is adapted to pull and release thewires of the control system 22. When the lever 30 is moved by the user,the actuator 28 is moved. The actuator 28 may be, for example, a drum orpulley rotatably connected to the control section 12 to pull one wirewhile releasing the other. In an alternate embodiment, the actuator maybe any suitable type of device, such as a rocker arm adapted to pull andrelease the wires of the control system 22. In another alternateembodiment, where the control system may have two or more pairs ofcontrol wires, the control section will have additional actuators andcorresponding controls to drive the additional pairs of bending controlwires. In still other alternate embodiments, the control section mayhave knobs with rack and pinion mechanisms or other suitable useroperated controls for the control system.

The shaft 14 is cantilevered from the control section 12. The flexibleshaft 14 includes the bending control wires of the control system 22, afiber optic image bundle, a fiber optic illumination bundle, and aworking channel. A port 60 for inserting instruments into the workingchannel 24 of the shaft is located on the control section 12. Thecontrol section 12 also has a light source post 62 for connecting alight source (not shown) to the illumination bundle. In addition, thecontrol section 12 has an eyepiece 63 for a user to view an imagetransmitted by the image bundle from the front end 20. In alternateembodiments, the flexible shaft may house different systems within. Theshaft 14 generally comprises a frame 26, a cover 32 and an objectivehead 34.

Referring also to FIGS. 2-3, a distal end of an endoscopic tool 36 isshown. The tool 36, in this example, is a medical retrieval tool. Thetool 36 is attached to the endoscope 10 and is configured to extend outof the distal end 20 of the shaft 14 from the working channel 24. Thetool 36 may be a Surgeon Controlled Basket Device (SCBD). The tool 36includes an assembly 33 which comprises a basket device 50 and a sheath56. The basket device 50 comprises a basket 52 at a distal end, and ashaft 54 extending through the sheath 56 to a control 37 (see FIG. 1) ata proximal end of the tool 36. The shaft 54 functions as a control wirefor moving the basket 52. The control 37 functions as a handle to insertthe tool 36 into the working channel 24, and as means to move the basketdevice 50 and sheath 56 longitudinally relative to each other. Thesheath 56 and basket device 50 are longitudinally movable relative toeach other to move the basket device 50 between a forward position and arearward position relative to the sheath 56. FIGS. 2 and 3 show theshaft (control wire) 54 moved forward relative to the sheath 56 suchthat the basket 52 is located out from a front end aperture 66 of thesheath 56. As shown in FIG. 4, in the forward position of the sheath 56on the basket device 50, the basket 52 is located inside the channel 57of the sheath 56; the basket 52 being collapsed by the sheath 56 into asmaller shape to fit inside the sheath 56.

A user, such as a surgeon for example, is able to operate the control 37to extend the distal end of the tool 36 out of the distal end of theendoscope 10. The user is also able to use the control 37 to move thesheath 56 and basket device 50 relative to each other to deploy thetool, capture an object(s) (such as a kidney stone fragment forexample), and retract the object back to the endoscope.

The basket 52 is comprised of a plurality of legs 70. The legs 70 extendfrom the distal end of the shaft 54 and are connected at a distal end ofthe basket 52. FIG. 2 shows the legs and basket in their natural homestate. The legs 70 have an inwardly bent section 72. This helps todefine a first basket cage section 74 and a second basket cage section76. The inwardly bent sections 72 define a reduced size neck 78 betweenthe two basket cage sections 74, 76. In the example embodiment shown,the legs 70 are comprised of superelastic material or shape memoryalloy, such as NITINOL for example. However, other materials might beused. The legs 70 are able to resiliently compress. The legs 70 haveinternal spring forces to be able to return to their normal size andshape when located out of the sheath.

As noted above, the basket 52 may be collapsed inside the sheath 56 asshown in FIG. 4. This helps to allow easy insertion of the tool 36through the working channel 24 of the endoscope 10. Referring also toFIG. 5, the basket device 50 may be moved relative to the sheath 56, asindicated by arrow A, to extend the basket 52 from the distal end of thesheath 56. FIG. 5 shows a first deployed position of the basket 52relative to the sheath 56. In this first deployed position, only aportion of the basket 52 is extended from the front end of the sheath.In particular, the first basket cage section 74 is deployed as shown.The legs 70 open at the first basket cage section 74 to allow the firstbasket cage section 74 to open. This allows the first basket cagesection 74 to capture an item, such as a stone fragment, therein. In oneexample, the first basket cage section 74 might be 6 mm in diameter inorder to be able to capture a fragment about 1 mm to 3-4 mm in size. Thesecond basket cage section 76 stays inside the sheath 56 in this firstdeployed configuration.

It is contemplated that control member 37 may be configured withdistinct markings and/or locking points to fix the basket at the first,second, or third deployment configuration and move between anyintermediate points as desired to facilitate appropriate control overthe basket in each deployment configuration.

Referring also to FIG. 6, the basket device 50 may be further movedrelative to the sheath 56, as indicated by arrow A, to extend the basket52 from the distal end of the sheath 56 a further distance than thatshown in FIG. 5. FIG. 6 shows a second deployed position of the basket52 relative to the sheath 56. In this second deployed position thesecond basket cage section 76 is fully extended out of the sheath 56and, thus, is able to spring back into its normal size and shape. Thisallowed the second basket cage section 76 to be used to capture an item,such as a stone fragment, therein. In one example, the second basketcage section 76 might be 11 mm in diameter in order to be able tocapture a fragment larger than that of the first basket cage section.Thus, with features as described in the above example, the basket 52 issized and shaped to be able to deploy in at least two deploymentconfigurations; with the first basket cage section for capturing smalleritems or with the additional second basket cage section for capturinglarger items.

Referring also to FIG. 7, the basket 52 may also be configured to deployinto a third deployment configuration. In this example, after deploymentinto the second deployment configuration shown in FIG. 6, the user maypress the distal end 80 of the basket 52 against a surface 82, such astissue of a patient. The legs 70 are sized, shaped and configured toallow the legs to deform at a predetermined stress to transform into asingle basket cage shape rather than the multiple basket cage shapesshown in FIGS. 2 and 6. The construction and geometry of the legs 70,when sufficient force is applied to the end 80, causes the inwardly bentsections 72 to flex outward to change the radius of curvature and pushoutwards, thereby eliminating the neck 78. This results in a much largersingle basket cage section 84 as shown in FIG. 7 with an enlargeddiameter, such as about 14 mm for example. The region at the distal tipwith a darkened appearance represents the first basket portion 74 in theexpanded configuration distally and the second basket portion 76 in theexpanded configuration proximally to create the third deploymentconfiguration.

In a conventional basket retrieval device, if the basket captured anitem which was too big to withdraw properly with the tool, the userwould have to cut the basket away from the endoscope. Features asdescribed herein, on the other hand, provide the ability to enlarge thebasket 50 into a third deployment configuration as described above. Withthis feature, the tool no longer needs to be cut away from the endoscopeif the item (stone fragment for example) is too large to be withdrawnthrough the endoscope. Instead, with features as described herein, theuser would capture items with by use of the first and/or seconddeployments described above, and if the item is too large to be removedthrough the endoscope working channel 24, the user can implement thethird deployment configuration to release the item from the basket 52.The user can then break the item into smaller sizes, such as bylithotripsy for example, and then use the tool 36 to remove the smallersize items through the endoscope's working channel.

The example described above is able to change the shape of the basket 52by the force applied at the surface 82. However, in an alternateembodiment, other shape memory properties of the superelastic materialcould be used to trigger the shape change, such as triggering changesbetween austentite and martensite configurations of NITINOL throughstress or temperature changes.

The example described above is able to provide three different captureconfigurations (FIG. 5, FIG. 6, and FIG. 7). It is contemplated that theconfiguration of FIG. 7 could also be used as a release configuration.This is able to be accomplished, in the above described example, byproviding the basket with two distinct deployable sections 74, 76, aswell as use of a shape change capability. With the addition of use of ashape change actuation event (such as the force applied to the end 80for example), the shape change capability can be used to release a stonewhich is too large to otherwise be withdraw through the endoscope. Inalternate examples, more or less than two different captureconfigurations could be provided, and more than one releaseconfiguration could be provided, and/or more than one shape changeactuation event could be provided.

An example embodiment may be provided in a medical retrieval toolcomprising a sheath; and a basket device connected to the sheath, wherethe basket device comprises a shaft and a basket located at a distal endof the shaft, where the shaft is movably located in the sheath. Thebasket may comprise a first basket cage section 74 and a second basketcage section 76. The first basket cage section may be located in frontof the second basket cage section. The basket may be configured to beextended from a distal end of the sheath in a plurality of deploymentmodes comprising: a first deployment mode where the first basket cagesection is deployed in a first fully expanded shape and the secondbasket cage section is located in the sheath; and a second deploymentmode where both the first basket cage section and the second basket cagesection are deployed out of the distal end of the sheath.

The basket device may comprise a plurality of legs joined at the shaftand joined at a distal end of the basket device, where the plurality oflegs form the first and second basket sections, and where the pluralityof legs each have an inwardly bent section forming a reduced size neckbetween the first and second basket sections. When the basket is in thesecond deployment mode, and when a front end of the basket is pressedagainst a surface with a predetermined force, the first and secondbasket cage sections may be configured to change shape into a singlebasket cage section which is larger than the second basket cage section.The basket may comprise superelastic material, and the basket may have adistal end which is configured to flatten when the distal end of thebasket is pressed against a surface. The first basket cage section maybe smaller than the second basket cage section. When in the seconddeployment mode, the first basket cage section may be about 40-60percent smaller in size than the second basket cage section. Inalternate configurations, the first basket cage section may be largerthan the second basket cage section. The plurality of deployment modesmay comprise a third deployment mode and, when in the third deploymentmode, and the basket may have a single basket shape with a size about15-35 percent larger than the second basket cage section in the seconddeployment mode.

It is contemplated that the first basket portion may be configured withlower hoop stress or lower bending stiffness than the second basketportion. It is contemplated that the first basket portion may beconfigured with a reduced diameter wire, may be chemically etched, maybe electro polished, may be flattened, and/or may be provided with amodified cross section such that the bending stiffness may be reduced inthe first basket portion. Modifying the basket wire of the first basketportion in this way may eliminate the need for a two-step heat treatmentprocess. In this example configuration, it is contemplated that only asingle heat treatment step may accomplish to desired structural changefrom the second deployment configuration to the third deploymentconfiguration upon the application of pressure at a distal end of thebasket section.

It is contemplated that the basket may comprise a first basket portionthat is separately heat treated and a second basket portion that isseparately heat treated. Subsequently, the first and second basketportions would be joined by welding, or some other method known in theart.

An example method may comprise providing a basket device, where thebasket device comprises a basket formed by a plurality of legscomprising superelastic material, where the legs are connected at distalends of the legs; shape setting, by a first heat setting, at least afirst portion of the legs to have a first shape; and shape setting, by asecond heat setting, at least a second portion of the legs to have asecond different shape.

The second shape may comprise a distal end of the basket having asubstantially flat shape. The plurality of legs may comprisesuperelastic material, and where the basket may have a distal end whichis configured to flatten when the distal end of the basket is pressedagainst a surface. The legs may be shaped into a first basket cagesection and a second basket cage section, where the first basket cagesection is located in front of the second basket cage section, where theplurality of legs are joined at a shaft of the basket device and joinedat a distal end of the basket device, and where the plurality of legseach have an inwardly bent section forming a reduced size neck betweenthe first and second basket sections. The legs may be shape memorytrained such that, when a front end of the basket is pressed against asurface with a predetermined force, the first and second basket cagesections are configured to change shape into a single basket cagesection which is larger than the second basket cage section. The firstbasket cage section may be formed smaller than the second basket cagesection. The first basket cage section may be about 40-60 percentsmaller in size than the second basket cage section and the legs aretrained such that, when a distal end of the basket is pressed against asurface with a predetermined force, the basket resiliently deforms intoa single basket shape with a size about 15-35 percent larger than thesecond basket cage section.

An example method may comprise forming a basket device, where the basketdevice comprises a basket at a distal end of a shaft, where the basketcomprises a plurality of legs forming a first shape with a first basketcage section and a second basket cage section, where the first basketcage section is located in front of the second basket cage section, andwhere the first basket cage section is smaller than the second basketcage section; and shape setting, by heat setting, at least a portion ofthe basket to have a different second shape when the basket is subjectedto a shape-memory transition stress and/or temperature, where thedifferent second shape comprises a basket cage which is larger than thesecond basket cage section. Features as described herein may be used toprovide an adjustable flexible stone retrieval basket, such as with aNITINOL basket for example. Features as described herein may be used toprovide a stone retrieval device comprising a basket, a sheath and ahandle. The basket may be made of NITINOL wires that are set to assumethe shape of the cage. In its normal state the NITINOL wires will alwaysassume the shape of the cage that it was set to, but when the basket isdrawn into a plastic sheath then the wires collapse and, thus, thebasket closes. An issue with conventional baskets is that they attainthe desired shape only at full deployment. With conventional baskets, acage shape at partial deployment is not ideal for capturing smallstones. With features as described herein, the proposed product willhave a desirable shape when only partially extended out of the sheath,as well as a different desirable shape when fully extended out of thesheath. This will provide a multi-shape and multi-deployment advantagein order to ease capture of either small stones or large stones.

Features as described herein may be provided with a composite basketcage having a small basket cage located in front of a larger basketcage. When the device is partially deployed, only the small basket cagewill come out of the sheath and aid in capture of smaller stones. Whenthe basket is fully deployed the entire composite structure is out ofsheath. In addition, when this basket is pressed against the anatomy ofa patient, then the small basket can flatten out and combine the twobasket cages to become part of an even larger single basket cage.

An example embodiment may be provided in a medical retrieval toolcomprising a sheath; and a basket device connected to the sheath, wherethe basket device comprises a shaft and a basket located at a distal endof the shaft, where the shaft is movably located in the sheath. Thebasket may comprise means for a first deployment relative to the sheathproviding a fully formed first basket cage section, means for a seconddeployment relative to the sheath providing a fully formed second basketcage section distinct from the first basket cage section, and means fortransforming the first and second basket cage sections into a relativelylarge basket cage formed by a combination of the first and second basketcage sections and resilient deformation of a neck between the first andsecond basket cage sections.

Features as described herein may be provided with a retrieval devicecomprising: a first basket portion; a second basket portion; and anouter sheath, wherein the retrieval device is capable of at least afirst deployment and a second deployment. The basket may furthercomprise a third deployment with a flat atraumatic distal end. The firstdeployment may produce the first basket portion with a smaller basketcircumference, and the second deployment may produce the second basketportion with a larger basket circumference.

An example manufacturing method may comprise applying a first heatsetting step to a NITINOL basket; and applying a second heat settingstep to the NITINOL basket to form the basket with a flat distal end.

It should be understood that the foregoing description is onlyillustrative. Various alternatives and modifications can be devised bythose skilled in the art. For example, features recited in the variousdependent claims could be combined with each other in any suitablecombination(s). In addition, features from different embodimentsdescribed above could be selectively combined into a new embodiment.Accordingly, the description is intended to embrace all suchalternatives, modifications and variances which fall within the scope ofthe appended claims.

1. A medical retrieval tool comprising: a sheath; and a basket deviceconnected to the sheath, where the basket device comprises a shaft and abasket located at a distal end of the shaft, where the shaft is movablylocated in the sheath; where the basket comprises a first basket cagesection and a second basket cage section, where the first basket cagesection is located in front of the second basket cage section, where thebasket is configured to be extended from a distal end of the sheath in aplurality of deployment modes comprising: a first deployment mode wherethe first basket cage section is deployed in a first fully expandedshape and the second basket cage section is located in the sheath; asecond deployment mode where both the first basket cage section and thesecond basket cage section are deployed out of the distal end of thesheath; and a third deployment mode, where the basket has a shape in thethird deployment mode which is larger than a shape of the basket in thesecond deployment mode, and where the basket is configured to changefrom the second deployment mode to the third deployment mode based uponthe basket being pressed against a surface.
 2. The medical retrievaltool as in claim 1 where the basket device comprises a plurality of legsjoined at the shaft, where the plurality of legs form the first andsecond basket sections, and where the plurality of legs each have aninwardly bend section forming a reduced size neck between the first andsecond basket sections.
 3. The medical retrieval tool as in claim 1where the basket is configured to transition from the second deploymentmode to the third deployment mode when a front end of the basket ispressed against the surface with a predetermined force.
 4. The medicalretrieval tool as in claim 1 where the basket has a distal end which isconfigured to flatten when the distal end of the basket is pressedagainst a surface.
 5. The medical retrieval tool as in claim 1 where thefirst basket cage section is smaller than the second basket cagesection.
 6. The medical retrieval tool as in claim 1 where the firstbasket cage section is formed of first portions of wires having a lowerbending stiffness than second portions of the wires at the second basketcage section.
 7. The medical retrieval tool as in claim 1 where, when inthe second deployment mode, the first basket cage section is about 40-60percent smaller in size than the second basket cage section.
 8. Themedical retrieval tool as in claim 1 where, when in the third deploymentmode, the basket has a single basket shape with a size about 15-35percent larger than the second basket cage section in the seconddeployment mode.
 9. A method comprising: providing a basket device,where the basket device comprises a basket formed by a plurality of legscomprising superelastic material; shape setting, by a first heatsetting, at least a first portion of the legs to have a first shape; andshape setting, by a second heat setting, at least a second portion ofthe legs to have a second different shape.
 10. The method as in claim 9where the second shape comprises a distal end of the basket having asubstantially flat shape.
 11. The method as in claim 9 where the baskethas a distal end which is configured to flatten when the distal end ofthe basket is pressed against a surface.
 12. The method as in claim 9where the legs are shaped into a first basket cage section and a secondbasket cage section, where the first basket cage section is located infront of the second basket cage section, where the plurality of legs arejoined at a shaft of the basket device, and where the plurality of legseach have an inwardly bent section forming a reduced size neck betweenthe first and second basket sections.
 13. The method as in claim 12where the legs are trained such that, when a front end of the basket ispressed against a surface with a predetermined force, the first andsecond basket cage sections are configured to change shape into a basketcage section which is larger than the second basket cage section. 14.The method as in claim 12 where the first basket cage section is formedsmaller than the second basket cage section.
 15. The method as in claim12 where the first basket cage section is about 40-60 percent smaller insize than the second basket cage section and the legs are trained suchthat, when the basket is pressed against a surface with a predeterminedforce, the basket resiliently deforms into a single basket shape with asize about 15-35 percent larger than the second basket cage section. 16.The medical retrieval tool as in claim 1 where the basket compriseswires forming the first basket cage section and the second basket cagesection, where portions of the wires at a junction between the firstbasket cage section and the second basket cage section have a lowerbending stiffness than other portions of the wires.
 17. A medicalretrieval tool comprising: a sheath; and a basket device connected tothe sheath, where the basket device comprises a shaft and a basketlocated at a distal end of the shaft, where the shaft is movably locatedin the sheath; where the basket is configured to be extended from adistal end of the sheath in a plurality of deployment modes comprising:a first deployment mode having a first size; a second deployment modehaving a second size, where the second size is larger than the firstsize; and a third deployment mode having a third size, where the thirdsize is larger than the second size, where the basket is configured totransition from the second deployment mode to the third deployment modebased upon the basket being pressed against a surface.
 18. The medicalretrieval tool as in claim 17 where the basket is configured to have thesecond size when the basket is fully extended from the distal end of thesheath and before the basket is pressed against the surface.
 19. Themedical retrieval tool as in claim 17 where the basket is configured toautomatically expand from the second size to the third size, with amiddle section of the basket expanding outward, when the basket ispressed against the surface with a predetermined force.
 20. The medicalretrieval tool as in claim 17 where the basket has a general hour-glassshape when the basket is fully extended from the distal end of thesheath and before the basket is pressed against the surface.